GardenWizzPlant Care Card

Common Alder

Alnus glutinosa · Tree

Hardiness
H7 Very hardy (to below −20°C)
Position
Full sun
Height × Spread
20–37 m × —
Soil
Moist but well-drained; tolerates poor soils; pH Acid, Alkaline, Neutral.
Flowering
—
Toxicity
No specific toxicity is listed by the RHS. This is not a guarantee of safety — check with a vet or the ASPCA before pets or children eat any plant.

The Gardening Year

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🪴 Plant out

Watch out for

Phytophthora root rot: Avoid waterlogged soils, ensure good drainage, and do not move infected soil or plant material.

Honey fungus: Improve soil drainage and air circulation; remove infected roots if possible to prevent spread.

Alder leaf beetle: Monitor for larvae in spring; severe infestations may require insecticidal treatment.

Alder sucker sawfly: Encourage natural predators like birds; manual removal of larvae if populations are high.

Slugs and snails: Use physical barriers, copper tape, or approved slug pellets around young plants.

Full guide: gardenwizz.com/plants/common-alder © GardenWizz — UK gardening encyclopedia